Documentation
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Index ¶
- Variables
- type FourSquaresSplitter
- type Proof
- type ProofCommit
- type ProofStructure
- func (s *ProofStructure) BuildProof(commit *ProofCommit, challenge *big.Int) *Proof
- func (s *ProofStructure) CommitmentsFromProof(g *gabikeys.PublicKey, p *Proof, challenge *big.Int) []*big.Int
- func (s *ProofStructure) CommitmentsFromSecrets(g *gabikeys.PublicKey, m, mRandomizer *big.Int) ([]*big.Int, *ProofCommit, error)
- func (s *ProofStructure) VerifyProofStructure(g *gabikeys.PublicKey, p *Proof) bool
- type SquareSplitter
- type SquaresTable
- type Statement
- type StatementType
Constants ¶
This section is empty.
Variables ¶
var ( ErrFalseStatement = errors.New("requested inequality does not hold") ErrUnsupportedSign = errors.New("unsupported sign: must be 1 or -1") )
Functions ¶
This section is empty.
Types ¶
type FourSquaresSplitter ¶
type FourSquaresSplitter struct{}
func (*FourSquaresSplitter) Ld ¶
func (*FourSquaresSplitter) Ld() uint
func (*FourSquaresSplitter) SquareCount ¶
func (*FourSquaresSplitter) SquareCount() int
type Proof ¶
type Proof struct {
// Actual proof responses
Cs []*big.Int `json:"Cs"`
DResponses []*big.Int `json:"ds"`
VResponses []*big.Int `json:"vs"`
V5Response *big.Int `json:"v5"`
MResponse *big.Int `json:"-"`
// Proof structure description
Ld uint `json:"l_d"`
Sign int `json:"sign"`
A uint `json:"a"`
K *big.Int `json:"k"`
}
func (*Proof) ExtractStructure ¶
ExtractStructure extracts the proof structure from proof
func (*Proof) ProvenStatement ¶
func (p *Proof) ProvenStatement() (StatementType, uint, *big.Int)
ProvenStatement returns the statement that this proof proves. Calling the second and third return parameters "factor" and "bound" respectively, then
factor*attribute - bound >= 0 or <= 0
where the inequality type is returned as the first parameter.
NB: this method does not verify the proof. Do not trust the output unless proof.Verify() has been invoked first.
type ProofCommit ¶
type ProofCommit struct {
// contains filtered or unexported fields
}
type ProofStructure ¶
type ProofStructure struct {
// contains filtered or unexported fields
}
func NewProofStructure ¶
func NewProofStructure(index, sign int, factor uint, bound *big.Int, splitter SquareSplitter) (*ProofStructure, error)
NewProofStructure creates a new proof structure for proving a statement of the form sign(factor*m - bound) >= 0.
index specifies the index of the attribute. splitter describes the method used for splitting numbers into sum of squares.
func (*ProofStructure) BuildProof ¶
func (s *ProofStructure) BuildProof(commit *ProofCommit, challenge *big.Int) *Proof
func (*ProofStructure) CommitmentsFromProof ¶
func (*ProofStructure) CommitmentsFromSecrets ¶
func (s *ProofStructure) CommitmentsFromSecrets(g *gabikeys.PublicKey, m, mRandomizer *big.Int) ([]*big.Int, *ProofCommit, error)
func (*ProofStructure) VerifyProofStructure ¶
func (s *ProofStructure) VerifyProofStructure(g *gabikeys.PublicKey, p *Proof) bool
type SquareSplitter ¶
type SquareSplitter interface {
// Ld returns the number of bits per square
Ld() uint
// SquareCount return the number of squares in result
SquareCount() int
// Split is the actual splitting function. On input delta, it should return array x such that sum_i x_i^2 = delta and len(x) = SquareCount()
Split(*big.Int) ([]*big.Int, error)
}
SquareSplitter provides a combined interface for all facets describing a method for splitting positive numbers into a sum of squares.
type SquaresTable ¶
type SquaresTable [][]int64
func GenerateSquaresTable ¶
func GenerateSquaresTable(limit int64) *SquaresTable
GenerateSquaresTable generates lookup table for splitting numbers into 3 squares containing entries up-to and including limit takes O(n^3/2)
func (*SquaresTable) Ld ¶
func (t *SquaresTable) Ld() uint
func (*SquaresTable) SquareCount ¶
func (t *SquaresTable) SquareCount() int
type Statement ¶
type Statement struct {
Sign int
Factor uint
Bound *big.Int
Splitter SquareSplitter
}
Statement states that an attribute m satisfies Sign*(Factor*m-Bound) >= 0, and that Sign*(Factor*m-Bound) can be split into squares with the given Splitter. E.g. if Factor = 1 then Factor*m >= Bound. Defaults to four square splitter when splitter is not specified.
func NewStatement ¶
func NewStatement(typ StatementType, bound *big.Int) (*Statement, error)
func (*Statement) ProofStructure ¶
func (statement *Statement) ProofStructure(index int) (*ProofStructure, error)
type StatementType ¶
type StatementType int
const ( GreaterOrEqual StatementType = iota LesserOrEqual )
func (StatementType) Sign ¶
func (typ StatementType) Sign() (int, error)
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